Page 2009 of 2267
Thermostat
REMOVAL AND INSTALLATION
1. Drain engine coolant.
2. Remove lower radiator hose.
3. Remove water inlet, then take out thermostat.
4. Before installing thermostat, remove all traces of liquid gasket
from mating surface of each part using a scraper.
5. Apply liquid gasket to water outlet, thermostat housing and
water inlet.
6. Install thermostat with jiggle valve uppermost.
After installation, run engine for a few minutes, and check
for leaks.
SLC564AA
SEC. 210-211Water outlet
16 - 21 (1.6 - 2.1, 12 - 15)
From oil cooler
From heater unit
16 - 21 (1.6 - 2.1, 12 - 15)
Up
Thermostat
Thermostat housing
Water inlet
16 - 21 (1.6 - 2.1, 12 - 15)
2.5±0.5
(0.098±0.020)
dia.2.5 (0.098)
3.5 (0.138)
Bolt hole
2.5±0.5 (0.098±0.020) dia.
2.5±0.5
(0.098±0.020) dia.Bolt hole
2.5±0.5 (0.098±0.020) dia.
2.5±0.5
(0.098±0.020) dia.
Unit: mm (in)
:N·m (kg-m, ft-lb)
SLC097 Air bleederUpper
Jiggle valve
ENGINE COOLING SYSTEMCD20T
Thermostat
LC-34
Page 2010 of 2267
INSPECTION
1. Check valve seating condition at ordinary temperatures. It
should seat tightly.
2. Check valve opening temperature and valve lift.
Valve opening temperature°C(°F) 82 (180)
Valve lift mm/°C (in/°F)More than 10/95 (0.39/203)
3. Then check if valve closes at 5°C (41°F) below valve opening
temperature.
SLC343
ENGINE COOLING SYSTEMCD20T
Thermostat (Cont’d)
LC-35
Page 2011 of 2267
Radiator
1Reservoir tank
2Reservoir tank hose
3Radiator cap
4Mounting bracket
5Upper radiator hose
6Mounting rubber
7Radiator
8Lower radiator hose
9Cooling fan
10Cooling fan motor
11Cooling fan motor shield
Cooling fan control system
Cooling fans are controlled by the ECM. For details, refer to EC
section (“COOLING FAN”,“Diagnostic Procedure”, EC-CD-
90).
Refilling engine coolant
For details on refilling engine coolant, refer to MA section
(“ENGINE MAINTENANCE”,“Changing Engine Coolant”,
MA-52).
NLC089
3.8 - 4.5
(0.39 - 0.45,
34 - 39)
4.0 - 4.5
(0.41 - 0.45,
36 - 39)
4.0 - 4.5
(0.41 - 0.45,
36 - 39)
3.25 - 4.25
(0.33 - 0.43,
28.8 - 37.6)
:N·m (kg-m, in-lb)
ENGINE COOLING SYSTEMCD20T
Radiator
LC-36
Page 2012 of 2267
Overheating Cause AnalysisNCLC0028
Symptom Check items
Cooling sys-
tem parts
malfunctionPoor heat transferWater pump malfunction Worn or loose drive belt
— Thermostat stuck closed—
Damaged finsDust contamination or
paper clogging
Mechanical damage
Clogged radiator cooling
tubeExcess foreign material
(rust, dirt, sand, etc.)
Reduced air flowCooling fan does not oper-
ate
—— High resistance to fan rota-
tion
Damaged fan blades
Damaged radiator shroud———
Improper coolant mixture
ratio———
Poor coolant quality———
Insufficient coolantCoolant leaksCooling hoseLoose clamp
Cracked hose
Water pump Poor sealing
Radiator capLoose
Poor sealing
RadiatorO-ring for damage, deterio-
ration or improper fitting
Cracked radiator tank
Cracked radiator core
Reservoir tank Cracked reservoir tank
Overflowing reservoir tankExhaust gas leaks into
cooling systemCylinder head deterioration
Cylinder head gasket dete-
rioration
ENGINE COOLING SYSTEM
Overheating Cause Analysis
LC-37
Page 2013 of 2267
Symptom Check items
Except cool-
ing system
parts mal-
function—Overload on engineAbusive drivingHigh engine rpm under no
load
Driving in low gear for
extended time
Driving at extremely high
speed
Powertrain system malfunc-
tion
— Installed improper size
wheels and tires
Dragging brakes
Improper ignition timing
Blocked or restricted air
flowBlocked bumper—
— Blocked radiator grilleInstalled car brassiere
Mud contamination or
paper clogging
Blocked radiator—
Blocked condenser
—
Installed large fog lamp
ENGINE COOLING SYSTEM
Overheating Cause Analysis (Cont’d)
LC-38
Page 2014 of 2267

Oil Pressure CheckNCL0011
Engine speed
rpmApproximate discharge pressure
kPa (bar, kg/cm2, psi)
600 More than 98 (0.98, 1.0, 14)
2,000 More than 294 (2.94, 3.0, 43)
6,000 More than 392 (3.92, 4.0, 57)
Oil Pump InspectionNCLC0013Unit: mm (in)
Body to outer gear radial clearance 0.250 - 0.325 (0.0098 - 0.0128)
Inner gear to outer gear tip clearance Below 0.18 (0.0071)
Body to inner gear clearance 0.030 - 0.085 (0.0012 - 0.0033)
Body to outer gear axial clearance 0.030 - 0.090 (0.0012 - 0.0035)
Inner gear to brazed portion of housing clearance 0.045 - 0.091 (0.0018 - 0.0036)
Regulator Valve InspectionNCLC0012Unit: mm (in)
Regulator valve to oil pump cover clearance 0.052 - 0.088 (0.0020 - 0.0035)
ThermostatNCLC0029
Valve opening temperature°C(°F) 82 (180)
Valve lift mm/°C (in/°F)More than 9/95 (0.35/203)
RadiatorNCLC0030
Unit: kPa (bar, kg/cm2, psi)
Cap relief pressureStandard 78 - 98 (0.78 - 0.98, 0.8 - 1.0, 11 - 14)
Limit 59 - 98 (0.59 - 0.98, 0.6 - 1.0,9-14)
Leakage test pressure157 (1.57, 1.6, 23)
SERVICE DATA AND SPECIFICATIONS (SDS)QG
Oil Pressure Check
LC-39
Page 2015 of 2267

Oil Pressure Check
Engine speed
rpmApproximate discharge pressure
kPa (bar, kg/cm2, psi)
Idle speed More than 78 (0.78, 0.8, 11)
3,200 314 - 392 (3.14 - 3.92, 3.2 - 4.0, 46 - 57)
Oil Pump Inspection
Unit: mm (in)
Body to outer gear clearance (radial) 0.114 - 0.200 (0.0045 - 0.0079)
Inner gear to outer gear tip clearance Below 0.18 (0.0020 - 0.0071)
Body to inner gear clearance 0.05 - 0.09 (0.0020 - 0.0035)
Body to outer gear clearance (axial) 0.05 - 0.11 (0.0020 - 0.0043)
Inner gear to brazed portion of housing clearance 0.045 - 0.091 (0.0018 - 0.0036)
Regulator Valve Inspection
Unit: mm (in)
Regulator valve to oil pump cover clearance 0.040 - 0.097 (0.0016 - 0.0038)
Thermostat
Valve opening temperature°C(°F) 82 (180)
Valve lift mm/°C (in/°F)More than 9/95 (0.35/203)
Radiator
Unit: kPa (bar, kg/cm2, psi)
Cap relief pressureStandard 78 - 98 (0.78 - 0.98, 0.8 - 1.0, 11 - 14)
Limit 59 - 98 (0.59 - 0.98, 0.6 - 1.0,9-14)
Leakage test pressure157 (1.57, 1.6, 23)
SERVICE DATA AND SPECIFICATIONS (SDS)SR20DE
Oil Pressure Check
LC-40
Page 2016 of 2267
Oil Pressure Check
Engine speed
rpmApproximate discharge pressure
kPa (bar, kg/cm2, psi)
Idle speed More than 59 (0.59, 0.6, 9)
2,000 294 (2.9, 3, 43)
Oil Pump Inspection
Unit: mm (in)
Body to outer gear clearance (radial) 0.114 - 0.200 (0.0045 - 0.0079)
Outer gear to inner gear clearance Less than 0.18 (0.0071)
Housing to inner gear clearance 0.05 - 0.09 (0.0020 - 0.0035)
Housing to outer gear clearance (axial) 0.05 - 0.11 (0.0020 - 0.0043)
Inner gear to housing clearance 0.045 - 0.091 (0.0018 - 0.0036)
Thermostat
Valve opening temperature°C(°F) 82 (180)
Valve lift mm/°C (in/°F)More than 10/95 (0.39/203)
Radiator
Unit: kPa (bar, kg/cm2, psi)
Cap relief pressureStandard 98 - 118 (0.98 - 1.18, 1.0 - 1.2, 14 - 17)
Limit 59 - 118 (0.59 - 1.18, 0.6 - 1.2, 8.6 - 17.1)
Leakage test pressure157 (1.57, 1.6, 23)
SERVICE DATA AND SPECIFICATIONS (SDS)CD20T
Oil Pressure Check
LC-41